Preparation and characterization of CuIn_1-xGa_xSe₂ nanopowders using solution growth technology for solar energy application

In this study, the CuIn1-xGaxSe2 nano-particles were prepared using the solution growth technology. The effects of [Ga]/[In+Ga] molar ratios in samples on the structural, electrical, and optical properties of the samples was investigated. X-ray diffraction patterns of samples revealed that the as-prepared samples are the chalcopyrite phase with preferential orientation of (112) crystal plane. The average particle size of samples obtained from the transmission electron microscopy is 10.73 nm after the 10 min. reaction in the solution. The direct energy band gap of thin films were in the range of 1.01∼1.27 eV, depending on [Ga]/[In+Ga] molar ratio in samples. The performance of dye-sensitized solar cells with the CuIn1-xGaxSe2 as the counter electrode was also investigated. The maximum solar to electrical power efficiency of dye-sensitized solar cells using the CuIn1-xGaxSe2 as the counter electrode approached of 5.57 %.